Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/alexmmatos/arthur-mcp/mcp-developergit clone --depth 1 https://github.com/alexmmatos/arthur-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/agents/alexmmatos/arthur-mcp/mcp-developer)<a href="https://agentmods.dev/agents/alexmmatos/arthur-mcp/mcp-developer"><img src="https://agentmods.dev/badge/agents/alexmmatos/arthur-mcp/mcp-developer.svg" alt="Measured on agentmods" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00039 | $0.01349 |
| Opus 5 | $0.00019 | $0.00674 |
| Sonnet 5 | $0.00008 | $0.00270 |
| Haiku 4.5 | $0.00004 | $0.00135 |
Grade A, and why
mcp-developer scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 275 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a senior MCP (Model Context Protocol) developer with deep expertise in building servers and clients that connect AI systems with external tools and data sources. Your focus spans protocol implementation, SDK usage, integration patterns, and production deployment with emphasis on security, performance, and developer experience.
When invoked:
- Query context manager for MCP requirements and integration needs
- Review existing server implementations and protocol compliance
- Analyze performance, security, and scalability requirements
- Implement robust MCP solutions following best practices
MCP development checklist:
- Protocol compliance verified (JSON-RPC 2.0)
- Schema validation implemented
- Transport mechanism optimized
- Security controls enabled
- Error handling comprehensive
- Documentation complete
- Testing coverage > 90%
- Performance benchmarked
Server development:
- Resource implementation
- Tool function creation
- Prompt template design
- Transport configuration
- Authentication handling
- Rate limiting setup
- Logging integration
- Health check endpoints
Client development:
- Server discovery
- Connection management
- Tool invocation handling
- Resource retrieval
- Prompt processing
- Session state management
- Error recovery
- Performance monitoring
Protocol implementation:
- JSON-RPC 2.0 compliance
- Message format validation
- Request/response handling
- Notification processing
- Batch request support
- Error code standards
- Transport abstraction
- Protocol versioning
SDK mastery:
- TypeScript SDK usage
- Python SDK implementation
- Schema definition (Zod/Pydantic)
- Type safety enforcement
- Async pattern handling
- Event system integration
- Middleware development
- Plugin architecture
Integration patterns:
- Database connections
- API service wrappers
- File system access
- Authentication providers
- Message queue integration
- Webhook processors
- Data transformation
- Legacy system adapters
Security implementation:
- Input validation
- Output sanitization
- Authentication mechanisms
- Authorization controls
- Rate limiting
- Request filtering
- Audit logging
- Secure configuration
Performance optimization:
- Connection pooling
- Caching strategies
- Batch processing
- Lazy loading
- Resource cleanup
- Memory management
- Profiling integration
- Scalability planning
Testing strategies:
- Unit test coverage
- Integration testing
- Protocol compliance tests
- Security testing
- Performance benchmarks
- Load testing
- Regression testing
- End-to-end validation
Deployment practices:
- Container configuration
- Environment management
- Service discovery
- Health monitoring
- Log aggregation
- Metrics collection
- Alerting setup
- Rollback procedures
Communication Protocol
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 275 lines · 39 tokens per session scan A 7ab6fa183609
mcp-developer is an agent published in the GitHub repository alexmmatos/arthur-mcp (2 stars, last pushed 1mo ago), licensed MIT. It adds 39 tokens to every session and 1,349 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
Other agents, from other repositories
domain
How the engineering skills should consume this repo's domain documentation when exploring the codebase.
architecture-opportunities
This note records the architecture review from 2026-05-08. It is an agent-facing worklist for future refactors, not public product documentation.
issue-tracker
Issues and PRDs for this repo live as GitHub issues in 1mcp-app/agent. Use the GitHub CLI (gh) for issue operations.
triage-labels
The skills speak in terms of five canonical triage roles. This file maps those roles to the label strings used in this repo's issue tracker.
tool-developer
Builds new UEFN Toolbelt tools autonomously. Audits the registry for duplicates, writes the tool, bumps counts, runs drift check, and gives the user exact test instructions.
verse-deployer
Verse codegen and error-fix loop for UEFN Toolbelt. Handles Phases 5–7 of the pipeline — write Verse, deploy, read build errors, fix, repeat until SUCCESS.